Signal lines in printed circuit boards, cables, and other conveyance structures exhibit transmission-line behavior for signals having a sufficiently high frequency components; that is, signals with transition times smaller than the electrical length of the wire or trace. A transmission line includes one or more signal line and, in most cases, one or more grounded conductors such as a ground plane, line, or shield. Signal lines and grounded conductors are separated by one or more dielectric materials. Signals traveling in the transmission line will result in an electric field in the dielectric material. Any dielectric material other than a perfect vacuum will have associated with it a dielectric loss, which can limit the useful distance a high-frequency signal can travel through the transmission line.